What are some examples of systems with time-dependent Hamiltonians?

[diegzumillo]

Hi all!
I'm starting to study the time evolution operator, and now i came up with this objective... i need a time dependent hamiltonian! since no fundamental interaction is time dependent i need to think of a system in such a configuration that i have a time dependency on H.
Anyway, if anyone has any idea i'd be very happy to discuss them! :D

 

[lbrits]

Not fundamental, but effective: An electron in a rotating magnetic field:
$$\mathbf{B}(t) = sin(\omega t) \mathbf{x} + \cos(\omega t) \mathbf{y}$$